When people think of the medical properties of marijuana, they immediately associate its effects with delta-9-tetrahydrocannabinol (THC), the most psychologically active compound in cannabis. But what most people don’t know is that there are actually 483 different identifiable chemical constituents found in cannabis.

Many of these constituents are non-psychoactive components, and many of them are found in other plants. Only 66 of these constituents—called cannabinoids—are unique to the Cannabis plant. But that does not mean there are 66 different cannabinoid effects or interactions. Most of the cannabinoids are closely related and oftentimes they work together to create the healing properties of pot. For example, in 2001, GW Pharmaceuticals found that only a combination of CBD and THC offered analgesic effects for MS patients. Taken alone, neither CBD nor THC was as effective in treating chronic pain as they were in combination.

Medical marijuana studies have shown that the non-psychoactive cannabinoids found in medical marijuana have medical properties. For example, cannabidiol (CBD) has sedative, analgesic and antibiotic properties, and appears to heighten the depressant effects and moderate the euphoric effects. And studies suggest that cannabigerol (CBG) may reduce intraocular pressure and contribute to marijuana’s antibiotic properties.

Here is a complete list of the cannabinoids found in marijuana, according to the Institute of Medicine’s March 1999 report titled “Marijuana and Medicine: Assessing the Science Base:”